How can the 44 Convertible run so much shallower than the competition? The tunnels are the key-Donald Blount and Associates designed the tunnels specifically for the props, reducing tip clearance to 2" or less. With most boats this size, about 4" of clearance is necessary; without it, inconsistent water velocity over the top of the prop causes vibration. And the more tip clearance you need, the bigger the tunnels have to be. The bigger the tunnels are, the less buoyancy your boat has. The less buoyancy, the deeper the boat sinks into the water, increasing draft. So why can't everyone else build with a 2" tip clearance? Blount and Associates has its own analytical design procedure that allows for selection and design around a prop with the least vertical prop-induced vibration. Net result: The 2" tip clearance in relatively small tunnels that would cause the boat to shake apart in most cases is free of excessive vibration, so you can run over shoals and shallows that would leave other 44' convertibles high and dry.